I can see it now:
from the t-rex:
the mobility (hunched over, running)
the legs,
the tail,
and the shape of the head

from the human:
half a brain,
the face,
various grunts and roars since it has half a brain,
and the shape of human arms... and you know what? Why not give the length of arms of the t-rex (same shape just larger to mach the body)